Alkaline earth metal petroleum sulfonate compositions



Patented Nov. 23, 1948 ALKALINE EARTH METAL PETROLEUM SULFONATE COMPOSITIONS Jacob Faust, Belleville, N. J., assignor to L. Sonnebom Sons, Inc., a corporation of Delaware No Drawing. Original application May 17, 1945,

Serial No. 594,369. Divided and this application December 10, 1946, Serial No. 715,337

9 Claims. ,(cl. 252-334) This invention relates to new and useful im- 3 provements in alkaline earth metal petroleum sulfonate compositions and is a division of my application, Ser. No. 594,369 filed May 1'1, 1945 now abandoned.

Substantially oil soluble alkaline earth metal petroleum sulfonates are used for a variety of purposes including as additives to lubricating oils, particularly aviation lubricants. The substantially oil soluble alkaline earth petroleum sulionates such as the calcium, barium and magnesium petroleum sulfonates, particularly when used as additive to lubricants, are usually employed in the form of concentrated oil solutions, 1. e., solutions in a suitable lubricating oil stock. The substantially oil soluble alkaline earth metal petroleum sulfonateahowever, when used in relatively high concentrations, tend to produce gel formation in their oil solutions, causing in many cases solidification of the entire mass. The gels are diificult to handle and temperatures as high as 300 F. are required to impart fluidity and pumpability thereto. Furthermore, blending operations of these sulfonates with the lubricating oils for which they are intended as an additive are rendered difilcult due to the relative lack of dispersibility of the gels in the oils.

The gelling problem is particularly bothersome in the production of the substantially oil soluble alkaline earth petroleum sulfonates. In accordance with conventional practice, substantiallyvoil soluble alkali metal petroleum sulfonate stocks are obtained by suitable neutralization and extraction of an oil layer derived from the sulfuric acid treatment of petroleum oil distillates. The resulting alkali metal petroleum sul-,

fonate stock is normally obtained in the form of a solution in oil, the latter being relatively tenaciously retained by the sulfonates and thus is conventionally termed in the art retained These retained oil-petroleum alkali metal petroleum sulfonate stocks may contain, depending upon the particular method of manufacture used, from about 10 to 75% sulfonates and from 25 to 90% retained oil. Conversion of these sulionate stocks to the alkaline earth metal sulionates is normally accomplished by contacting the former with aqueous solutions of water-soluble alkaline earth metal salts, having as the metal component one selected in accordance with the sulionate desired to be produced. After thorough intermixing and agitation of the reactants, separation is permitted to take place into an aqueous 2 of'salts. The oil layer is washed for the removal of salts and is thereafter dehydrated for the removal of water. Usually, in the dehydration step when the water content reaches between 2 and 5%, substantially spontaneous gelling occurs, solidifying the entire product.

I have discovered that it is possible to eliminate gelling oi ml'neral oil solutions of alkaline earth metal petroleum sulfonate's in normally gel forming concentrations. In accordance with the invention, I obtain a substantially non-gelled or non-gelling oil solution of a substantially oil soluble alkaline earth metal petroleum sulfonate in normally gel forming concentration by the use of relatively small amounts of a member selected from the group consisting of phthalic acid esters o1 aikylene glycols, phthalic acid esters of alkylene glycol ethers and alkyl phthalates. These materials may be added to an alkaline earth metal petroleum sulionate oil composition to either break an already formed gel or to prevent the formation of a gel therein. Alternatively, they may be added as part of the conversion procedure from substantially oil soluble alkali metal to substantially oil soluble alkaline earth metal petroleum sulfonates. When adding, however, a gel preventative in accordance with the invention in the process of manufacture of the substantially oil soluble alkaline earth metal petroleum sulfonates from a substantially oil soluble alkali metal petroleum sulfonate-retained oil composition, I prefer to admix the preventative with the oil composition prior to the conversion step. The above enumerated materials are all substantially oil soluble and remain in the oil phasefthus being available in their gel preventing action both during the dehydration step and in the finished product. Good results are, for

instance, obtained with phthalic acid ester of a 2.0% of my novel gel breaking or preventing agent, by,weight ,of the substantially oil soluble alkaline earth metal petroleum sulfonates present in the oil or to be formed in oil solution in the course of its method of manufacture by suitable conversion.

aaaavae 3 The following examples are furnished by way of illustration and not of limitation:

Example I 1 liter of a 30% solution of sodium petroleum sulfonates in oil was heated to 200 F. and admixed with 1 liter of a 30% aqueous barium chloride solution. The mixture was permitted to settle on a steam bath overnight whereupon onds at 210 F. The dehydrated barium petroleum sulfonate-oil composition obtained when proceeding without the addition of the phthalate constituted a stiff rubbery gel.

Example II IV possessed after dehydration a furol viscosity at 210 F. of 265 seconds and was fluid at room temperature.

Example VI The procedure of Examples IV and V was carried out, converting the substantially oil soluble sodium petroleum sulfonate to the substantially all soluble magnesium salt. The magnesium sulfonate solution in oil, after dehydration, had a furol viscosity at 210 F. of 285 seconds and was fluid at normal temperatures.

The substantially oil soluble alkali metal or I alkaline earth metal petroleum sulfonates herein 1 liter of a solution of sodium petroleum sulfonate in oil was mixed with 2% dimethyl phthalate (by weight of sulfonate present) and converted to the calcium salt by reacting witha 30% aqueous calcium chloride solution at 140 F. After separation of the layers and removal of the lower aqueous layer, the calcium sulfonate solution in oil was washed .with water to free it from unreacted calcium chloride and was finally subjected to dehydration by heating, while stirring with air at 300 F. The dehydrated solution possessed a furol viscosity of 39 seconds at 210 F.

- The same'conversion was conducted in the absence of a gel preventing agent. The finished calcium sulfonate solution had a gelling point of 125 F. and a furol viscosity at 210, nearly ten times as great as the solution dehydrated in the presence of dimethyl phthalate, namely 310 seconds.

Example III Example IV Proceeding in accordance with Example II, 2% of the phthalic acid ester of diethylene glycol monoethyl ether (by weight of sulfonate present) was used as gel preventing agent and the calcium sulfonate oil solution obtained after dehydra tion had a furol viscosity at 210 F. of 173 seconds and was fluid at room temperature.

Example V Duplicating the procedure of Example IV, a 30% solution of sodium petroleum sulfonate in oil was converted to the barium salt. The finished barium sulfonate solution in oil containing the same gel reventing agent used'in Example referred to may comprise either true mahogany petroleum sulfonates'or compositions of petroleum mahogany sulfonates containing up to an equal amount by weight of petroleum green sulfonates.

Petroleum mahogany sulfonates are, as such, substantially-water insoluble and oil soluble, whereas normally petroleum green sulfonates are substantially all insoluble and water soluble. Petroleum mahogany sulfonates and sulfonic acids. however, have the capacity when in oil solution of solubilizing' green petroleum sulfonic acids or sulfonates into the oil phase up to an equal amount by weight. Wherever in the specification and claims, therefore, reference is made to substantially oil soluble or oil dissolved alkali metal or alkaline earth metal petroleum sulfonates, I mean to include thereby oil soluble petroleum mahogany alkali metal or alkaline earth metal sulfonates as well as substantially oil soluble mixtures of such mahogany petroleum sulfonates wtih alkali metal or alkaline earth metal green petroleum sulfonates containing up to an equal amount by weight of the green sulfonates.

The foregoing description is for purposes of illustration and not of limitation and it is therefore myintention that the invention be limited only by the appended claims or theirequivalents ates in amount sufilcient to substantially prevent gelling of said alkaline earth metal petroleum sulfonate-petroleum hydrocarbon solution.

2. A- substantially non-gelling alkaline earth metal petroleum sulfonate solution in mineral oil in accordance with claim 1, in which said group member is present in from 0.5 to 5.0% by weight of alkaline earth metal petroleum sulfonate present.

3. A substantially non-gelling alkaline earth metal petroleum sulfonate solution in mineral oil in accordance with claim 1, in which said group member is present in from 1.0 to 2.0% by weight of alkaline earth metal petroleum sulfonate present.

4. A substantially non-gelling alkaline earth metal petroleum sulfonate solution in mineral oil which comprises a petroleum hydrocarbon oil, a substantially oil soluble alkaline earth metal petroleum sulfonate dissolved in said hydrocar bon oil in normally gel forming amounts, and a substantially oil soluble phthalic acid ester of an alhl ether-oi an alkylene glycol in amount suflicient to substantially prevent gelling of said alkaline earth metal petroleum sulfonate-petroleum hydrocarbon solution.

5. A substantially non-gelling alkaline earth metal petroleum sulionate solution in mineral oil in accordance with claim 4, in which said phthalic acid ester of an alkyl ether of an alkylene glycol is the phthalic acid ester of monoethyl ether of dlethylene glycol.

6. A substantially non-gelling alkaline earth.

metal petroleum sulfonate solution in mineral oil in accordance with claim 4, in which said kali metal petroleum sulfonate in petroleum hy drocarbon oil, and containing at least one memher selected from the group consisting of substan- 25 tially oil-soluble, phthallc acid esters of alkylene glycol ethers and alkyl phthalates with an aqueous solution of an alkaline earth metal salt to thereby convert the substantially oil soluble a1- kali metal petroleum sulionate in said hydrocarbon oil solution into the substantially oil soluble alkaline earth metal petroleum sulfonate. separating the oil phase from the aqueous phase and dehydrating the oil phase, said alkali metal petroleum sulfonate' being present in amount sufficient to yield a final conversion of normally gel forming concentration and said group memher being added in amount suflicient to substantially prevent gelling oi the saidconversion product during and after dehydration.

8. The improvement in accordance with claim 7 in which said group member is' dimethyl phthalate.

9. The improvement in accordance with claim 7 in which said group member is substantially oil soluble phthalic acid ester of an alkyl ether of an alkylene glycol.

JACOB FAUST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,113,754 Zimmer et al. Apr. 12, 1938 2,329,474 Lazar et al. Sept. 14, 1943 2,361,806 Merrill Oct. 31, 1944 2,378,820 Amott June 19, 1945 30 2,401,614 Chechot et al. June 4, 1946 

